title: Changes in risk of immediate adverse reactions to iodinated contrast media by repeated administrations in patients with hepatocellular carcinoma.
abstract: BACKGROUND
  To elucidate whether repeated exposures to iodinated contrast media increase the risk of adverse reaction.
  
  
  METHODS
  We retrospectively reviewed 1,861 patients with hepatocellular carcinoma who visited authors' institution, a tertiary referral center, between 2004 and 2008. We analyzed cumulative probability of adverse reactions and risk factors. We categorized all symptoms into hypersensitivity reactions, physiologic reactions, and other reactions, according to the American College of Radiology guidelines, and evaluated each category as an event. We estimated the association between hazard for adverse reactions and the number of cumulative exposures to contrast media. We also evaluated subsequent contrast media injections and adverse reactions.
  
  
  RESULTS
  There were 23,684 contrast media injections in 1,729 patients. One hundred and thirty-two patients were excluded because they were given no contrast media during the study period. Adverse reactions occurred in 196 (0.83%) patients. The cumulative incidence at 10(th), 20(th), and 30(th) examination was 7.9%, 15.2%, and 24.1%, respectively. Presence of renal impairment was found to be one of risk factors for adverse reactions. The estimated hazard of overall adverse reaction gradually decreased until around 10(th) exposure and rose with subsequent exposures. The estimated hazard of hypersensitivity showed V-shaped change with cumulative number of exposures. The estimated hazard of physiologic reaction had a tendency toward decreasing and that of other reaction had a tendency toward increasing. Second adverse reaction was more severe than the initial in only one among 130 patients receiving subsequent injections.
  
  
  CONCLUSIONS
  Repeated exposures to iodinated contrast media increase the risk of adverse reaction.
authors.affiliation: Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.
authors.forename: Naoto
authors.initials: N
authors.lastname: Fujiwara
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Tateishi
authors.forename: Masaaki
authors.initials: M
authors.lastname: Akahane
authors.forename: Masataka
authors.initials: M
authors.lastname: Taguri
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Minami
authors.forename: Shintaro
authors.initials: S
authors.lastname: Mikami
authors.forename: Masaya
authors.initials: M
authors.lastname: Sato
authors.forename: Koji
authors.initials: K
authors.lastname: Uchino
authors.forename: Kouji
authors.initials: K
authors.lastname: Uchino
authors.forename: Kenichiro
authors.initials: K
authors.lastname: Enooku
authors.forename: Yuji
authors.initials: Y
authors.lastname: Kondo
authors.forename: Yoshinari
authors.initials: Y
authors.lastname: Asaoka
authors.forename: Noriyo
authors.initials: N
authors.lastname: Yamashiki
authors.forename: Tadashi
authors.initials: T
authors.lastname: Goto
authors.forename: Shuichiro
authors.initials: S
authors.lastname: Shiina
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Yoshida
authors.forename: Kuni
authors.initials: K
authors.lastname: Ohtomo
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Koike
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000139:chemically induced* / Q000453:epidemiology*; D003287:Contrast Media / Q000008:administration & dosage / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007275:Injections, Intravenous; D007455:Iodine; D008113:Liver Neoplasms / Q000139:chemically induced* / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012306:Risk; D055815:Young Adult
chemical_list: D003287:Contrast Media; D007455:Iodine